Superconducting noise-source for ultra-low temperatures

The device operates at temperatures <300 mK and comprises a hafnium microbridge superconducting aluminum tunnel junction both integrated into common coplanar waveguide. matches with planar antenna as an optical blackbody frequencies 600-700 GHz. terminal is the output in 1-2 GHz frequency range. temperature can be set range of 0.4-9 K calibrated using shot noise junction. Temperature modulation each sources performed independently direct current which transit them from to normal state characteristic times <0.1 ms heating power ~ 1 μW. Keywords: Superconducting microbridge, junction, thermodynamic noise, thermometry.